Method of making luminous signs



May 6, 1952 D. M. M GILL METHOD OF MAKING LUMINOUS SIGNS- Filed Dec. 13, 1949 Dennis M. McGi/l IN V EN TOR.

Patented May 6, 1952 METHOD (is-MAKING L 'UMINOUS SIGNS Dennis McGill... Lancaster. Pa., assignor of; wentyrfiveypencent to Hugh: Chl,iSti, .Cocoli;

Application Decemberlii, 1949, Serial'No;-132;71'3

3 1 Claims.

Thisrinvention relates. to the class of signs and more: particularly: to: an. advertising. sign or thetlike which. makes use of the inherent luminosity-in the selected material from which the lettersof the sign are. made.

whichnthe symbols are made;

under the name Plexiglas.

weaken, this material...

its surfaces.

size.

from blanks of, suitable size.

of the sign are made.

will weaken the sign.

for each symbol or letter.

is quite pleasing in appearance.

An. object ofthisinvention is) to produce a; the. means used to make theluminous-signs. novel sign formed. from relatively strong, and wherein: rigid symbols secured together by aznovel method- Figure :1 is a tperspectivewiewzoi the. die-prefand in sucha manner as to make, full use of; erably.:used to-iorm asymbol froma; suitable; the inherent luminosity of the material, from blank;

Figure 2 is a plan view, of :azblank; usedinu A material which ispreferably usedgin the forming:a-symbol;. manufactureof the-signs :is-knownto the trade Figure 3 1s an elevational View; of; a fini she,d- This material is symbolv made; by. the; method; contemplat d: y: of: the. acrylic resin group, of plastics and is the present invention; and; thermoplastic; and will soften;at;temperatures Figuregt is a; sectional view as taken along; of 220" to; 320i F. It will not become liquid lineA-A of. Figure,.3 but when heated;may. be; easily; twisted, bent, With continuingreference to the accompany. shaped or stretched. Successive heatings do not ing reference drawingswherein; like; reference;

numerals designate;similar,;-parts throughout the This material has the additional property, various views, reference numeral [0 generally; important forthe'purpose of this invention, in designates a blank which is stamped from, a the fact that it bends light rays so as; to emit sheet of the material to be used. The blank them along its edges and from fractures upon I0 is ofv such-size and shape-so thatwvhen it is Thusly, this material shows a placed between male and female dies l2 and I4 luminous edgewhenthe pieces are of substantial respectively a finished symbol generally indie However, when these pieces are below a cated by reference numeral [6 will be formedcertainzwidth with respect to the thickness it which will make full use of the material of the will lose; its; luminous quality. Thus, it is very blank.

critical that,,-a sign using thismaterial bemade Referring now tothe male die l2 it will be seen that such is formed with a symbol l8 formed If the signs to be made from this material thereon whichhas its side walls 20 formed with; are not made. of 'sufficiently: large sized pieces, approximately a 15 bevel rearwardly. Furthertheluminous: quality will'be severely reduced. more, as at 22 the forward edges of the symbol Thus, it is an additional object of the invention. I8 are rounded for apurpose that will be readily to produce means having a high degree of understood after consideration of the further luminosity in which the strength of the sign description below. is not materially reduced and in which full use The male die I4 is formed with a recess 24 is made of the blanks from which the symbols therein adapted to mate with the projecting y ma us f a symbol I8 of the die l2. curved back for the symbols, such are composed. The blank [0 is heated to a temperature of of no h m ri l o iv the f l l m about 300 F. and then placed between dies l2 effect without adding un ec y depth ich and M. The blank 10 may be heated by passing through a steam heated chamber or any other t another ObJe t 0f the ve t o is to D suitable zone of heat. After the blank has been duce a Sign which will have two luminous edges placed between the dies 12 and [4, the dies are pressed together to form the symbol I6.

Still u r ObJGOtS 0f the mventlon are to symbol is allowed to cool and then removed after p oduc a Sign which is Strong. durable, highly which the edges 26 thereof are sanded to bring fli t in p rati n. simpl in c nstruction and forth the inherent luminosity of the Plexiglas" manufacture, relatively inexpensive and adapted to provide a, flat even surface for mounting and to bring more material used into view, and which to bring forth the true shape of the symbol by removing uneven edges.

These, together with the various ancillary With reference to Figure 4 it will be seen that the letter is formed with two divergent out.

objects of the invention which will become apparent as: the. following description proceeds;

are attained by this :method of making. luminoussigns; a preferred manner being. best understood with reference to .the accompanying; drawings i. wherein it is shown-by. way.- of example only.

The

wardly extending portions 28 and 30 due to the 15 bevel in the side walls 20 of the male portion of the die. A central connecting portion 32 having a radius of curvature of at least three times the thickness of the material connects the outwardly extending portions 28 and 30 and together these members form an extremely strong symbol. In order to form completed signs out of the symbol 16 when finished, these symbols may merely be secured to a backing plate by cementing the rear surface of the central connecting portion 32 to said backing plate. Any other convenient means for securing the symbol [6 to the backing plate may be used, however, it is preferable to secure the symbols by a means remote from the edges 26 so that no shadow or member may cover the edges to mar their luminous and pleasing appearance.

A clear plastic face plate may be used and the symbols may be mounted on the rear side thereof with their point of attachment the luminous edges of the symbols themselves. The symbols are then viewed through the sheet. A clear plastic cement such as ethylene dichloride securely attaches the symbols to the face plate and does not interfere with the viewing of the luminous edges whatsoever.

Since from the foregoing, the advantageous results of this method of producing luminous signs is readily apparent, further description is believed to be unnecessary.

However, since numerous modifications will readily occur to those skiiled in the art after a consideration of the foregoing specification and accompanying drawings, it is not intended to limit the invention to the precise method used and described but all suitable modifications thereof may be resorted to which fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A method of producing a self-illuminable sign comprising the steps of stamping blanks from a flat sheet of resinous plastic material, passing said blanks through a zone of heat, placing said blanks between male and female dies, pressing said dies together to transform the flat blanks into symbols of trough-shaped form allowing said symbols to cool, removing said symbols and then sanding the inner and outer edges thereof to effect edge-lighting of said symbols and securing said symbols in spaced relationship to each other to spell out the desired sign by means attaching said symbols to a backing member at a point remote from said edges.

2. The method of making up a self-illuminable .luminescent sign component susceptible of reflecting and glowing from a suitable source of light; the method steps consisting of first molding and transforming a flat sheet of moldable transparent light-reflecting acrylic plastic of prerequisite glossiness, size and thickness into a symbol of given shape and design whose molded portions are smooth, glossy and channel-shaped in cross-section, and second, abrading the respective inner and outer endless light-emitting marginal edges of the then existing flanges of said symbol to thus dull and render the same luminescent and to effect edge-lighting, the overall channel-shaped portion of said symbol providing the desired strength for light-reflecting properties and contrast between itself and said edges.

3. The method of producing a sign letter or an equivalent symbol which consists in following these steps; namely, first stamping a letter from a flat sheet of transparent acrylic plastics possessed of moldable properties and of a given minimum size and minimum thickness and Whose marginal edges are substantially flat, second, heating said letter to a degree of moldable plasticity, third, pressing the same in a mold and transforming it from its original fiat form to a form which is channel-shaped in crosssection and thus providing two spaced parallel flanges connected by a bight portion with said flanges in divergent relation, and fourth, abrading the marginal edges of said flanges, whereby to thus provide a letter which presents forwardly viewable spaced parallel edges in the same plane and wherein said edges, acting in conjunction with the letter proper not only delineate the outline desired, but are edge-lighted.

DENNIS M. MCGILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,285,963 Gits et a1. June 9, 1942 2,302,918 Smith Nov. 24, 1942 2,342,237 Barbieri Feb. 22, 1944 OTHER REFERENCES Pearson: Piping light with acrylic materials," Modern Plastics, August 1946, pages 123-7, 18-55E 

